1981 Yamaha 650 Maxim exhaust issues?

[marcdjr]

white smoke out of left exhaust when burning hot. Does this entail a leak? Or that there is some junk burning off?

[DrBob]

I little white smoke when you first fire it up can be caused by condensation in the pipe. But this should go away as the bike warms up, not get worce. The white smoke from a hot motor can be a sign of oil burning. I would perform a leak-down test to check crankshaft seal integrity. But as a quick check pull the plugs, and see if one on a left cylinder is kind of black and maybe a little wet or oily. If so, the problem is with that cylinder. Check compression and leak down on that cylinder first.